Installation:
Pesgalaxy 1.50 has to be installed before!
Start the Installer and choose your PES 2013 folder and follow the instructions. The Installer may need a few minutes to start.
Start the game with PESGalaxySwitch.exe inside the Pesgalaxy.com patch folder in your PES 2013 folder.
If you want to play online switch to Online Mode in the switch. For offline go back to default.
Scoreboards and other things can be selected with the Switch.
If you want to play without the patch just start the normal pes2013.exe.

Troubleshooting: If you have crashes in ML, especially Europa League, switch back to default Adboards and then choose your adboards again.